Dwarf Orange Crayfish are referred to as CPOs. The two main things to keep in mind are their need for oxygenated water and that they can be aggressive.
You can use an air-pump, line and air-stone. Personally I prefer a Hagen submersible filter, it injects air directly into the outflow. This helps recreate the basic environment required for a species adapted for life in a river.
CPOs seem to vary greatly in aggressiveness but it is wise to give then lots of hiding places and not overstock. I would suggest a baseline of three gallos for obe, and at least a gallon for each additional crayfish.